Re: Concurrency

[Tom Tromey]

Stefan> Could someone complete the above with a description of how
Stefan> let-bindings work (and/or how they interact with buffer-local
Stefan> bindings)?

A let binding is always thread-local.  This is true whether the variable
is buffer-local or not.

The view within a single thread is basically the same as how elisp works
today.

The interaction of let-bindings and buffer-local bindings is
complicated, but I think really no different from before.  At least,
that was our goal, of course there could be bugs.

Stefan> Also, a list of bugs/problem/issues would be handy,

* Documentation; NEWS, as you said, but also the lisp reference manual.

* The current code makes no attempt to portable, it relies on POSIX
  threads and the GNU __thread extension.  This is not too hard to fix.
  I think it is reasonably important to keep __thread on systems that
  support it, for performance.

* Suppose you have existing elisp that creates a process with a filter,
  and the filter changes a let-bound variable, and the "outer" elisp
  blocks in sit-for waiting for the filter to do its thing.  Nothing in
  the current code guarantees that the process filter will be run in the
  "correct" thread.

* There may be oddities with redisplay running in the "wrong" thread.

* Keyboard-local variables and let-bindings may not work together as
  expected.

I'm sure there are more, this is all I remember offhand.

Stefan> PS: And place this info in a file in the `concurrent' branch.

I hope someone else can do that.

Tom